• Araujo, Jp
• Amorim, Lm
• Wahl, U.
• Da Costa Pereira, Lmd
• Da Silva, Mr
• Da Silva, Dj
• Correia, Jg

Abstract

We have studied the influence of electronic doping on the preferred lattice sites of implanted Co-61, and the related stabilities against thermal annealing, in silicon. Using the beta(-) emission channeling technique we have identified Co on ideal substitutional (ideal S) sites, sites displaced from bond-centered towards substitutional (nearBC) sites and sites displaced from tetrahedral interstitial towards anti-bonding (near-T) sites. We show clearly that the fractions of Co on these lattice sites change with doping. While near-BC sites prevail in n(+)-type Si, near-T sites are preferred in p(+)-type Si. Less than similar to 35% of Co occupies ideal S sites in both types of heavily doped silicon, showing that the majority of implanted Co forms complex defect structures. Implantation-induced defects seem to getter more efficiently Co in lightly doped n-type than in heavily doped n(+)-or p(+)-type silicon. The formation of CoB pairs in p(+)-type silicon and its possible influence on the lattice sites is discussed.

Topics

• impedance spectroscopy
• laser emission spectroscopy
• Silicon
• annealing
• interstitial
• defect structure